Improvement in pressure blower-wheels



B. F. STURTEVANT.

.Pres sure Blower Wheel.

Patented Feb. 22,- 1870.

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Letters Patent No. 100,236, dated February 22, 1870.

IMPROVEMENT IN PRESSURE BLOWER-WHEELS.-

The Schedule referred to in these Letters Patent and making part of thesame To all whom it may concern: 4

,Be it known that I, B. F. STURTEVANT,'Of Jamaica Plain, in the countyof Norfolk, and State of Massachusetts, have invented an Improvement; inPressure Blower-Wheels; and I do hereby declare that the following,taken in connection with the drawings, which accompany and form part ofthis specification, is a description of my invention sufficient toenable those skilled in the artto practice it.

In blowers designed to deliver large quantities of air under pressure,for blowing iron furnaces and other objects, great attention has to bepaid to the form and proportions of the rotary blast-wheel in or-' derto secure the maximum effect withthe minimum of power.

In blowers made by'me heretofore, under Letters Patent of the UnitedStates, which have been granted for my inventions, I have substantiallythe same proportion of area of inlet for the shrouded blast-wheel to thearea of its outlet, that I have in the wheel in which my presentinvention is embodied, but in my aforesaid patented construction I havenot the same inclosed cubic capacity for air between .the inlet andoutlet that I have in this improved wheel, because the rings whichshroud the tiin-blades in former constructions are straight in the lineof a cross-section, taken diametrically through the wheel, or in otherwords, the shroudings are hollow conic frustra, while in my improvedwheel the shrouding's are made as dishing-rings, presenting theirconcave surfaces toward each other, so that the cubic capacity of thewheel is increased by the amount of the outward swell or convexity ofthe shroudings between the in let and outlet of the wheel, therebyincreasing the' reservoir of air from which the discharge takes place,

and the efi'ective action of the wheel.

Figural shows a section taken through my improved blast-wheel, in aplane at right angles toits axis, and

Figure 2 is a section taken inthe plane of the axis.

The wheel is made with three hubs and three sets of arms, the outer armsbeing fixed to rings a, which make the inlets to the wheel.

To the rings a the shroudings b are fixed,as well 2 as to fans 0, andthe arms on the center hub are united to the inner edges Jot the fans,stays (l proceeding from each arm to the outer end of the next adjacentfan.

inner to the outer edges, and the shroudings are made similarly convexto fit upon the sides of the fans to which the shroudings are united.

Heretofore blast-wheels have been made, as indioat-ed by the dottedlines seen in fig. 2, in which oonstruction the sides of the fansweremade substantially straight from their inner to their outer edges, andthe. shroudings'were made with a plain conical dishing form, or as conicfrustra, instead of in the concavo-convex dishing form shown in fig. 2.

By this improvement the annular rings of space represented in fig. 2, asbounded by the dotted lines and shroudings, are added to the internalcapacity of my wheel, in which air is stored, as in a reservoir,adjacent to the outlet, from which the air is forcibly delivered fromthe wheel.

I claim a blast-wheel, made with the dishing concave-convex shrouding,substantially as described.

B. F. STUBTEVANT.

Witnesses;

J. B. CROSBY, L. H. LATiMER.

The sides of each fan are made convex from the

